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gerrit-public.fairphone.software / kernel / msm-4.9 / 621c5d66633242ad2d1f824dfb7bae84753b3b3d / . / fs / ext4 / bitmap.c
blob: 3285aa5a706af3f97c6a182a12304c7478177d9d [file] [log] [blame]
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]1/*
Mingming Cao617ba132006-10-11 01:20:53 -0700[diff] [blame]2 * linux/fs/ext4/bitmap.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 */
9
10#include <linux/buffer_head.h>
Mingming Caodab291a2006-10-11 01:21:01 -0700[diff] [blame]11#include <linux/jbd2.h>
Christoph Hellwig3dcf5452008-04-29 18:13:32 -0400[diff] [blame]12#include "ext4.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]13
Theodore Ts'of6fb99c2012-06-30 19:14:57 -0400[diff] [blame]14unsigned int ext4_count_free(char *bitmap, unsigned int numchars)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]15{
Akinobu Mita6017b482012-07-30 14:41:08 -0700[diff] [blame]16 return numchars * BITS_PER_BYTE - memweight(bitmap, numchars);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]17}
18
Darrick J. Wong41a246d2012-04-29 18:33:10 -0400[diff] [blame]19int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
20 struct ext4_group_desc *gdp,
21 struct buffer_head *bh, int sz)
22{
23 __u32 hi;
24 __u32 provided, calculated;
25 struct ext4_sb_info *sbi = EXT4_SB(sb);
26
27 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
28 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
29 return 1;
30
31 provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
32 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
33 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
34 hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
35 provided |= (hi << 16);
36 } else
37 calculated &= 0xFFFF;
38
39 return provided == calculated;
40}
41
42void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
43 struct ext4_group_desc *gdp,
44 struct buffer_head *bh, int sz)
45{
46 __u32 csum;
47 struct ext4_sb_info *sbi = EXT4_SB(sb);
48
49 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
50 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
51 return;
52
53 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
54 gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
55 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
56 gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
57}
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]58
59int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
60 struct ext4_group_desc *gdp,
Tao Ma79f1ba42012-10-22 00:34:32 -0400[diff] [blame]61 struct buffer_head *bh)
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]62{
63 __u32 hi;
64 __u32 provided, calculated;
65 struct ext4_sb_info *sbi = EXT4_SB(sb);
Tao Ma79f1ba42012-10-22 00:34:32 -0400[diff] [blame]66 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]67
68 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
69 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
70 return 1;
71
72 provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
73 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
74 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
75 hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
76 provided |= (hi << 16);
77 } else
78 calculated &= 0xFFFF;
79
80 if (provided == calculated)
81 return 1;
82
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]83 return 0;
84}
85
86void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
87 struct ext4_group_desc *gdp,
Tao Ma79f1ba42012-10-22 00:34:32 -0400[diff] [blame]88 struct buffer_head *bh)
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]89{
Tao Ma79f1ba42012-10-22 00:34:32 -0400[diff] [blame]90 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]91 __u32 csum;
92 struct ext4_sb_info *sbi = EXT4_SB(sb);
93
94 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
95 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
96 return;
97
98 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
99 gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
100 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
101 gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
102}